The External Genitalia Score (EGS): A European Multicenter Validation Study.

Area of Science:

• Pediatric endocrinology
• Neonatology
• Genetics

Background:

• Standardized description of external genitalia is crucial for assessing children, especially those with atypical genitalia.
• Existing methods may lack comprehensive standardization for diverse presentations.

Purpose of the Study:

• To validate the External Genitalia Score (EGS) for describing external genitalia in infants.
• To establish reference values for the EGS in preterm and term infants up to 24 months.
• To correlate EGS scores with anogenital distances (AGDs).

Main Methods:

• A European multicenter validation study involving 686 term and 181 preterm infants, plus 111 with atypical genitalia.
• The External Genitalia Score (EGS), adapted from the external masculinization score, uses a 0-12 scale suitable for both sexes.
• Reliability assessed using interclass correlation coefficient (ICC); cross-sectional data collected.

Main Results:

• Excellent and good interclass correlation coefficients (ICC) for EGS in typical and atypical genitalia, respectively.
• Established median EGS reference values across different gestational ages for males, with EGS consistently 0 for females.
• Anogenital distance ratio (AGDl/u) showed significant differences between males, females, and infants with differences of sex development (DSDs), correlating with EGS in males.

Conclusions:

• The External Genitalia Score (EGS) is a validated and reliable tool for describing external genitalia in infants up to 24 months.
• EGS facilitates standardized clinical assessment, aids decision-making, and supports multicenter research.
• The study provides valuable reference data for EGS and its correlation with AGDs in pediatric populations.